1. Field of the Invention
The present invention relates to DC to DC converters, and more particularly to converter oscillators of the ringing choke type adapter for use in insect killing devices.
2. Description of the Prior Art
DC to DC conversion has had extensive applications in the past. Such converters can be found in gaseous lamps, automotive ignition systems of the capacitor discharge type, in laser pumping circuit and many other applications. Most frequently converters of the foregoing kind lacked the requisite efficiency for portable use. In particular devices like bug killers used by campers require portable battery power and thus the manner in which that power is used is of a paramount importance. The typical prior art converters normally experience substantial power losses during the switching transient of each oscillation. In the typical ringing choke configuration the collector winding develops current levels which are quickly above the saturated conduction levels of the base. At this point the base drive becomes insufficient to maintain the switching transistor in saturated conduction causing a slow turn-off with its attendant losses.
In the past various techniques were developed to improve this switching transient, both for optimization of efficiency and to improve frequency control. In each instance the improvements entail circuit complexity or the use of special purpose elements and their related expense.